Objective To investigate the clinical characteristics of exogenous lipoid and to explore the characteristics of the elderly with the disease. Methods 14 cases of elderly patients with exogenous lipoid in Beijing Hospital were analyzed. Results Among the 14 patients(7 male and 7 female), main symptoms included dyspnea(50.0%), cough(35.7%), and the common signs were crackles(28.6%)and wet rales(21.4%). For exogenous lipoid pneumonia, the most common causes of inhalation of lipoid substances included chronic constipation, nasal cavity diseases such as rhinitis(35.7%). Some of elderly dementia patients may wrong inhale lipoid substances(21.4%). X ray or CT features of exogenous lipoid showed a tumor-like mass or lesions(42.9%)and the exudative plaque(64.3%), both of which were easily misdiagnosed as tumor.All of the 14 cases(100%)were misdiagnosed as pneumonia or , and finally confirmed by pathological diagnosis.Among the 14 cases, 2 cases were diagnosed by cytopathology of bronchial alveolar lavage fluid or by transbronchial lung biopsy, 10 cases were diagnosed by invasive examination methods like lobe resection, and 2 cases were confirmed by autopsy.At present, there is still a lack of effective treatment methods for exogenous lipoid pneumonia. Conclusions Due to the basal disease(such as constipation)action, the elderly may easily have access to exogenous lipoid with atypical symptoms, might have more serious manifestations than younger adults, and may have X ray or CT imaging similar to lung cancer or pneumonia.So it is often misdiagnosed.If the patients cannot be timely diagnosed and the causes cannot be removed, it is likely to cause chronic interstitial fibrosis or death.Clinicians must increase the awareness of, and take into account the possibility of lipoid pneumonia, especially meeting the elderly patients with dry cough and dyspnea, rales or crackles and X-ray or CT tumor-like imaging as main manifestation resembling pulmonary inflammation or tumor without treatment futility after common antibiotic treatment. Key words: Lung disease, interstitial; Lipids